Overview: The main projects in my laboratory focus on animal models of drug addiction using rats. We commonly utilize intravenous drug self-administration methodology in conjunction with behavioral and neurochemical analyses to assess alterations in motivational, emotional and brain region-specific neurochemical status as the result of drug experience.
Studying factors contributing to drug use and abuse: Human emotion plays a major role in the initiation and maintenance of drug abuse, including the tendency to relapse back to drug use after abstinence. Ultrasonic vocalizations (USVs) elicited by rodents are known to communicate emotionally relevant information between conspecifics. We consider USVs to be a highly translational animal model of emotion during drug use. In our laboratory, we routinely collect and analyze USV data during all stages of our drug self-administration studies to gain insight to emotional processes over the course of drug experience. We have found that patterns and types of USVs resulting from drug experience are highly dependent on duration of drug use and the type of self-administered drug (e.g., cocaine versus morphine versus ethanol). These findings indicate experience-dependent emotional aspects of drug use and distinct emotional and/or motivational factors contributing to different drugs of abuse.
Using in vivo microdialysis and HPLC analyses of dopamine and/or serotonin in conjunction with drug self-administration procedures, we have found thathighly stimulating environments and the presence of drug-associated cueshave profound effects on mesolimbic neurochemical responses in the presence and absence of drug availability. These neurochemical responses appear to underlie motivational aspects of drug-taking behavior.
Relapse to drug use is often precipitated by cued memories of drug use.Through the use of USV recording and analyses, we can follow drug-associated learning as it develops during drug experience. We have found that individual differences in the propensity to associate cocaine with cocaine-associated cues (as indicated by the magnitude of USV responses in a drug-paired environment) are highly predictive of future drug-taking behavior. By targeting drug-associated USVs, we can test the effects of specificpharmacological agents and behavioral manipulations on cocaine-associated learning.
Collaborative Studies: We have additional studies associated with ongoing collaborative relationships with other laboratories within the College of Pharmacy, Waggoner Center, Institute of Neuroscience and Behavioral Neuroscience Area.
Undergraduates: We often have slots for volunteer undergraduate research assistants who can make multi-semester commitments to working in the laboratory.